This consultation was open from:
February 23, 2026
to April 9, 2026
Decision summary
An amendment Environmental Compliance Approval (ECA) has been granted to Greenstone Gold Mines GP Inc. to amend existing ECAs No. 0735-C9PMD6 issued on April 25, 2022, and No. 5375-DQ9KZ8 issued on January 21, 2026, to facilitate the operations phase of the Greenstone Gold Mine located at 7921 Highway 11, Geraldton, Municipality of Greenstone.
Location details
Site address
7921 Highway 11
Geraldton
Municipality of Greenstone,
ON
Canada
Site location details
7921 Hwy 11, Greenstone, Ontario, P0T 1M0, Canada
Site location map
The location pin reflects the approximate area where environmental activity is taking place.
View this location on a map opens link in a new windowProponent(s)
Greenstone Gold Mines GP Inc.
7921 Highway 11
Geraldton,
ON
P0T 1M0
Canada
Decision details
An amendment Environmental Compliance Approval (ECA) has been granted to Greenstone Gold Mines GP Inc. to amend existing ECAs No. 0735-C9PMD6 issued on April 25, 2022, and No. 5375-DQ9KZ8 issued on January 21, 2026, to facilitate the operations phase of the Greenstone Gold Mine located at 7921 Highway 11, Geraldton, Municipality of Greenstone, District of Thunder Bay.
The approved new works mainly include the following:
- operation of effluent pipelines
- construction and operation of tailings reclaim/discharge lines
- addition of seepage collection pond T2, which will consequently be converted to a pump-back system, as construction of downstream toe berm/buttress through the placement of fill material is required for the West Dam
- operations of the TMF with approved starter dams and then raising the TMF dams to a crest elevation of 347 m (Stage 2), with no effluent from the TMF or process plant discharging to land or to any surface water feature, nor conveyed to the Effluent Treatment Plant (ETP) for discharge into the Kenogamisis Lake
- modify the Works description to reflect the ultimate TMF dam crest elevation of 365 metres; and
- realigning and extension of the southeast seepage collection ditch by a total length of approximately 1,945 metres, with grades ranging from 0.1% to 0.6% along the Southeast and East dams, discharging to existing Pond T1.
Phosphorus has been historically elevated in Kenogamisis Lake and above the Provincial Water Quality Objectives for the protection of aquatic life in certain locations in the lake. GGM has implemented the best available phosphorus treatment technology, but the proposal will increase the load of phosphorus to Kenogamisis Lake as a result of the project discharges. To address concerns with this proposal, GGM will implement an enhanced monitoring program to evaluate the risk of their discharges and to assess potential changes to phosphorus concentrations in Kenogamisis Lake.
GGM will report to the Ministry of the Environment, Conservation and Parks and sample any cyanobacteria (blue-green algae) blooms observed during routine sampling events throughout Kenogamisis Lake to ensure risks due to these events are communicated to users within the broader watershed.
Effects of consultation
No comments were received.
Supporting materials
View materials in person
Some supporting materials may not be available online. If this is the case, you can request to view the materials in person.
Get in touch with the office listed below to find out if materials are available.
435 James Street South
3rd Floor, Suite 331B
Thunder Bay,
ON
P7E 6S7
Canada
How to Appeal
This instrument decision can be appealed. You have 15 days from August 5, 2026 to begin the appeal process.
Carefully review the information below to learn more about the appeal process.
How to appealClick to Expand Accordion
Start the process to appeal
If you’re an Ontario resident, you can start the process to appeal this instrument decision.
First, you’ll need to seek leave (i.e. get permission) from the relevant appellate body to appeal the decision.
If the appellate body grants leave, the appeal itself will follow.
Seek leave to appeal
To seek leave to appeal, you need to do these three things:
- prepare your application
- provide notice to the minister
- mail your application to three parties
1. Prepare your application
You’ll need to prepare an application. You may wish to include the following things in your application:
- A document that includes:
- your name, phone number, fax number (if any), and/or email address
- the ERO number and ministry reference number (located on this page)
- a statement about whether you are a resident in Ontario
- your interest in the decision, and any facts you want taken into account in deciding whether you have an interest in the decision
- the parts of the instrument that you’re challenging
- whether the decision could result in significant harm to the environment
- the reason(s) why you believe that no reasonable person – having regard to the relevant law and to any government policies developed to guide decisions of that kind – could have made the decision
- the grounds (facts) you’ll be using to appeal
- the outcome you’d like to see
- A copy of the instrument (approval, permit, order) that you you are seeking leave to appeal. You’ll find this in the decision notice on the Environmental Registry
- Copies of all supporting documents, facts and evidence that you’ll be using to appeal
What is considered
The appeal body will consider the following two questions in deciding whether to grant you leave to appeal:
- is there is good reason to believe that no reasonable person, with respect to the relevant law and to any government policies developed to guide decisions of that kind, could have made the decision?
- could the decision you wish to appeal result in significant harm to the environment?
2. Provide your notice
You’ll need to provide notice to the Minister of the Environment, Conservation and Parks that you’re seeking leave to appeal.
In your notice, please include a brief description of the:
- decision that you wish to appeal
- grounds for granting leave to appeal
You can provide notice by email at minister.mecp@ontario.ca or by mail at:
College Park 5th Floor, 777 Bay St.
Toronto, ON
M7A 2J3
3. Mail your application
You’ll need to mail your application that you prepared in step #1 to each of these three parties:
- appellate body
- issuing authority (the ministry official who issued the instrument)
- proponent (the company or individual to whom the instrument was issued)
Greenstone Gold Mines GP Inc.
7921 Highway 11
Geraldton,
ON
P0T 1M0
Canada
Registrar, Ontario Land Tribunal
655 Bay Street, Suite 1500
Toronto, Ontario
M5G 1E5
(416) 212-6349
(866) 448-2248
OLT.Registrar@ontario.ca
Include the following:
This is not legal advice. Please refer to the Environmental Bill of Rights for exact legal requirements. Consult a lawyer if you need help with the appeal process.
Connect with us
Contact
Client Services and Permissions Branch
40 St. Clair Avenue West
Floor 2
Toronto,
ON
M4V 1M2
Canada
Original proposal
Proposal details
This proposal is for an amendment to the Environmental Compliance Approval (ECA) No. 0735-C9PMD6 for various water management ponds and collection ditches serving Greenstone Gold Mines Tailings Management Facilities located at 7921 Highway 11, in Geraldton, Municipality of Greenstone, District of Thunder Bay, Ontario.
Due to the topography of the area, there is a large additional area outside of the Waste Rock Storage Area (WRSA) D that would be directed to the contact water ditch if a non-contact water diversion berm and channel was not in place. The diversion berm and channel are designed to direct non-contact water away from ditch D2-A and Pond D2.
The purpose of this application is to amend the ECA No. 0735-C9PMD6 to permit a non-contact water diversion berm and channel along the perimeter of ditch D2-A and Pond D2. There is no change to the WRSA seepage water collection or conveyance to Effluent Treatment Plant for treatment and discharge.
Supporting materials
View materials in person
Some supporting materials may not be available online. If this is the case, you can request to view the materials in person.
Get in touch with the office listed below to find out if materials are available.
40 St. Clair Avenue West
Floor 2
Toronto,
ON
M4V 1M2
Canada
Comment
Commenting is now closed.
This consultation was open from February 23, 2026
to April 9, 2026
Connect with us
Contact
Client Services and Permissions Branch
40 St. Clair Avenue West
Floor 2
Toronto,
ON
M4V 1M2
Canada
Comments received
Through the registry
0By email
0By mail
0